The following relates to chargers for electrical appliances, and especially to chargers for flashlights.
Secondary (rechargeable) batteries have become increasingly popular as an energy source for flashlights and other portable electrical appliances. One factor that influences the acceptance of these batteries, and the appliances that use them, is the convenience and ease of use of the requisite charger. In some cases, convenience can be enhanced when the batteries need not be removed from the appliance and can be charged in situ.
One flashlight and charging unit is disclosed in U.S. Pat. No. RE37,092 entitled Flashlight and Recharging System Therefor. The flashlight includes a barrel and an enlarged head. A guide plate located on the enlarged head provides an alignment feature that aligns a pair of flashlight charging contacts with a pair of terminals in the charging unit for releasably holding the flashlight in its charging receptacle. The charging receptacle grips the head portion of the flashlight with a pair of spring-loaded jaws. The flashlight is inserted in the receptacle by pressing the flashlight barrel between the jaws and moving the head of the flashlight axially.
According to the '092 patent, locating the guide plate on the head of the flashlight provides greater leverage for removing the flashlight from the charging unit than would otherwise be available if the contacts and guide plate were located at a lower position on the flashlight, such as on a tapered portion or the barrel. The charging unit also includes a single forward facing light emitting diode (LED) that, according to the patent, indicates when the flashlight is being charged.
The assignee of the '092 patent also markets a flashlight under the designation Stinger® HP™. The Stinger HP flashlight includes an enlarged, generally conical head and a cylindrical barrel. The flashlight also includes an enlarged body portion located immediately beneath the conical head. The guide plate and charging contacts are located on the enlarged body portion.
Another example of a flashlight and charging base is disclosed in U.S. Patent Publication No. 2006/0232239A1, published Oct. 19, 2006. The flashlight includes a pair of annular charging contacts that extend circumferentially around the barrel of the flashlight. The charging base includes a corresponding pair of contacts that serve the dual function of holding the flashlight in the charger and conducting electrical energy to the flashlight contacts. The charging base also includes a head section adapted to receive the enlarged head of the flashlight so that the corresponding flashlight and charger contacts are axially aligned. Forward facing red and green charge status LEDs are located near an LED display located at the front of the charging base.
The assignee of the '239 Publication also markets a flashlight and charging base under the designation Magcharger® Model No. RX1019. While the RX1019 charging base does not include an alignment recess, the contacts are located similarly to those disclosed in the '092 patent, and a pair of pivotally mounted jaws are located on either side of a flashlight barrel receiving area. The barrel causes the jaws to open when the flashlight is removed from the charging base; the jaws ordinarily remain open after the flashlight is removed. Reinserting the flashlight in the barrel receiving region causes the barrel to depress jaw portions located near the rear thereof, thus closing the jaws. A single red LED shines downwardly from the bottom of the base. The charging base also includes a head section similar to that disclosed in the '239 Publication.
While these devices allow the flashlight batteries to be recharged in situ, there remains room for improvement. For example, inserting the flashlights in and/or removing them from their respective charging units can require the application physical force sufficient to move the respective jaws. The application of such force can make it more difficult for the user to determine if the flashlight has been properly inserted. If not properly inserted, the batteries will not be charged, which unfortunately may not be noticed until the user has an immediate need for the flashlight.